Contents

The R143s are numbered 8101-8312. The 212 cars were expected to provide enough service for years, but the fast growth of the Williamsburg neighborhood overloaded the L by mid-2006.[3]

The R143s are the first 60-foot (18.29 m) B Division cars built for the New York City Subway system since the R42 from 1969, the first NTT model for the B Division, and the first automated fleet in the subway system. They are currently based at East New York Yard. The R143s are similar to the slightly newer R160s; however, the two car types can not be interchanged with each other.[4]

Like the R142s, R142As and R188s, the R143s feature electronic strip maps with all stops on the L route.

Unlike the rest of the NTT fleet, the R143s are equipped with interior LED screens, which take the place of the MTA Arts for Transit cards that are usually located there. These screens can display advertisements, public safety announcements, and other information.[5] Several R160s were similarly retrofitted with LCD screens after they were delivered. However, the LCD screens on the R160s have the capabilities to display multiple colors instead of only red, orange, and green.

The contract for the R143 was put out for bidding in January 1998. The initial contract called for 100 sixty-foot cars that would come in five-car sets. The new cars would be expected to have automatic PA announcements, high efficiency lighting, emergency intercom and customer alarms, AC propulsion motors, speedometers and event recorders, electronic information display signs, artwork, a central diagnostics monitoring system, microprocessor controlled air compressor, brake and communication systems, roof mounted microprocessor controlled HVAC, and to be compliant with ADA requirements.[6]

Kawasaki Rail Car, Inc. was awarded a $190 million contract for 100 new B Division cars in late December 1998, with an option for 112 more cars.[7] The new design was based on the A Division'sR142A, which Kawasaki also built,[8] and incorporated many features from the R110A and R110B prototypes. The cars were built with an average cost of about $1.5 million per car.

Delivery of the cars began in late 2001. A 30-day revenue acceptance testing with one train of eight cars (8101-8108) began on December 4, 2001.[9][10] According to Kawasaki, the test was "extremely successful".[8] The cars began running on the Canarsie Line (L train) on February 12, 2002, where they have been assigned to.[11] All 212 cars were delivered by March 2003.[12]

Along with displacing older equipment from the Canarsie Line, the R143s also displaced the R42s on the now-extended weekend M shuttle service on the BMT Myrtle Avenue Line, when that line became the first BMT Eastern Division line to be placed in weekend One Person Train Operation (OPTO) service. The R143s on the M were later displaced by the R160As in February 2008. OPTO service was also tested on the L during mid-2005, but it ended due to safety issues.[13][14]

Cars 8205-8212 were originally delivered with experimental Siemens traction motors to test the traction motors that would be later found in R160B cars 8843-9102. These cars were eventually refitted with the Bombardier MITRAC traction motors found on all other R143s.[15]

On June 21, 2006, an eight-car R143 train overshot the bumper at the end of the tracks in the Canarsie Yard after the operator suffered a seizure. The first car, 8277, suffered significant damage and was stripped of damaged parts before being sent to the Kawasaki plant in Yonkers to receive repairs. The other cars in the set (8278-8280) suffered minor body damage and were moved to the 207th Street Yard and repaired. Eventually, 8277 was sent back to New York City Transit property and repaired. By 2016, car 8277 was finally recoupled with 8278-8280, but the consist needed component upgrades to become operational.[16] The set returned to service in December 2017.[a]

In 2017, a set of R143s was equipped with measuring gauges to test out the curve radius and gangway flex in the existing 60-foot long cars in order to collect data for evaluating the future R211T order.[b][better source needed]

1.
Kawasaki Heavy Industries
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/kaʊ. əˈsɑːki/ is a Japanese public multinational corporation primarily known as a manufacturer of motorcycles, heavy equipment, aerospace and defense equipment, rolling stock and ships. It is also active in the production of industrial robots, gas turbines, boilers, the company is named after its founder Shōzō Kawasaki, and has dual headquarters in Chūō-ku, Kobe and Minato, Tokyo. KHI is known as one of the three major industrial manufacturers of Japan, alongside Mitsubishi Heavy Industries and IHI. Prior to World War II, KHI was part of the Kobe Kawasaki zaibatsu, after the war, KHI became part of the DKB Group. Kawasaki is active in a range of the aerospace industry. It is currently developing two large, next-generation aircraft, the XP-1 maritime patrol airplane and the XC-2 transport aircraft, Kawasaki also builds helicopters, including the BK117, jointly developed and manufactured with MBB. It also produces the CH-47J / JA helicopter, in the commercial aviation business, the company is involved in the joint international development and production of large passenger aircraft. It is involved in joint development and production of the Boeing 767, Boeing 777 and Boeing 787 with The Boeing Company, and the 170,175,190 and 195 jets with Empresa Brasileira de Aeronáutica. It is also involved in the joint international development and production of engines for passenger aircraft such as the V2500, the RB211/Trent, the PW4000. Kawasaki also works for the Japan Aerospace Exploration Agency, the Company was responsible for the development and production of the payload fairings, payload attach fittings and the construction of the launch complex for the H-II rocket. It continues to provide services for the H-IIA rocket, main products Aircraft Space systems Helicopters Simulators Jet engines Missiles Electronic equipment Kawasaki is Japan’s largest manufacturer of rolling stock. It began operations in the industry in 1906 and it manufactures express and commuter trains, subway cars, freight trains, locomotives, monorails and new transit systems. Kawasaki is also involved in the development and design of high-speed trains such as Japan’s Shinkansen and its product range include high-performance LNG and LPG carriers, container ships, bulk carriers and VLCCs, as well as submarines. The Company is also involved in the development of offshore structures, Kawasaki also produces marine machinery and equipment, including main engines, propulsion systems, steering gears, deck and fishing machinery. It also offers industrial plant engineering from design to sales, main products Industrial plants Industrial robots Aerodynamic machinery Hydraulic equipment Kawasaki is involved in the development of equipment that prevents pollution in a wide range of industries. Among the leading products are fuel gas desulfurization and denitrification systems, the Company also supplies municipal refuse incineration plants, gasification and melting systems, sewage treatment and sludge incineration plants. Kawasaki has also been developing systems that enable a range of municipal and industrial waste to be recovered, recycled. The company offers of storage solutions for LNG, Kawasaki’s portfolio also includes retractable roofs, floors and other giant structures, for construction, Kawasaki produces products such as wheel loaders, tunnel machines, rollers, snowplows and purpose specific loaders

2.
Yonkers, New York
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Yonkers is the fourth most populous city in the U. S. state of New York, and the most populous city in Westchester County, with a population of 195,976. It is an suburb of New York City, directly to the north of the Bronx. Yonkerss downtown is centered on a known as Getty Square. The area also houses significant local businesses and non-profits, and serves as a retail hub for Yonkers. This grant was purchased in July 1645 by Adriaen van der Donck, van der Donck was known locally as the Jonkheer or Jonker, a word from which the name Yonkers is directly derived. Van der Donck built a saw mill near where the Nepperhan Creek met the Hudson, van der Donck was killed in the Peach War. His wife, Mary Doughty, was taken captive and ransomed later, near the site of van der Doncks mill is Philipse Manor Hall, a Colonial-era manor house which today serves as a museum and archive, offering many glimpses into life before the American Revolution. The original structure was built around 1682 by Frederick Philipse and his wife Margaret Hardenbroeck, Frederick was a wealthy Dutchman who by the time of his death had amassed an enormous estate, which encompassed the entire modern City of Yonkers, as well as several other Hudson River towns. Philipses great-grandson, Frederick Philipse III, was a prominent Loyalist during the American Revolution, all the lands that belonged to the Philipse family were confiscated and sold. For its first two hundred years, Yonkers was a farming town with an active industrial waterfront. Yonkerss later growth rested largely on developing industry, in 1853, Elisha Otis invented the first safety elevator and the Otis Elevator Company, opened the first elevator factory in the world on the banks of the Hudson near what is now Vark Street. It relocated to larger quarters in the 1880s, the community was incorporated as a village in the northern part of the Town of Yonkers in 1854 and as a city in 1872. In 1874 the southern part of Yonkers, including Kingsbridge and Riverdale, was annexed by New York City as The Bronx, in 1898, Yonkers voted on a referendum to determine if they wanted to become part of New York City. Still, some call the city the Sixth Borough referring to its location on the New York City border, its urban character. The New York City and Northern Railway Company connected Yonkers to Manhattan, a three-mile spur to Getty Square existed until 1943. Aside from being a center, Yonkers also played a key role in the development of entertainment in the United States. In 1888, Scottish-born John Reid founded the first golf course in the United States, St. Andrews Golf Club, bakelite, the first completely synthetic plastic, was invented in Yonkers circa 1906 by Leo Baekeland, and manufactured there until the late 1920s. Early in the 20th century, Yonkers also hosted a brass era automobile maker, Colt Runabout Company, despite the cars seemingly glowing performance, Yonkers was also the headquarters of the Waring Hat Company, at the time the nations largest hat manufacturer

3.
Lincoln, Nebraska
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Lincoln is the capital of the U. S. state of Nebraska and the county seat of Lancaster County. The city covers 92.81 square miles with a population of 277,348 in 2015 and it is the second-most populous city in Nebraska and the 72nd-largest in the United States. The statistical area is home to 345,478 people, making it the 105th-largest combined statistical area in the United States, the city was founded in 1856 as the village of Lancaster on the wild salt marshes of what was to become Lancaster County. In 1867, the village of Lancaster became Nebraskas state capital and was renamed Lincoln, bertram G. Goodhue designed state capitol building was completed in 1932 and is the second tallest capitol in the United States. As the city is the seat of government for the state of Nebraska, the state, the University of Nebraska was founded in Lincoln in 1867. The university is the largest in Nebraska with 25,006 students enrolled and is the citys third-largest employer, other primary employers fall within the service and manufacturing industries, including a growing high-tech sector. The region makes up a part of what is known as the greater Midwest Silicon Prairie, designated as a refugee-friendly city by the U. S. Department of State in the 1970s, the city was the twelfth-largest resettlement site per capita in the United States by 2000. Refugee Vietnamese, Karen, Sudanese, and Yazidi people have resettled in the city. Lincoln Public Schools during the year of 2016–17 provided support for approximately 3,200 students from 118 countries. Prior to the westward of settlers, the prairie was covered with buffalo grass. Plains Indians, descendants of peoples who occupied the area for thousands of years, lived in. The Pawnee, which included four tribes, lived in villages along the Platte River, an occasional buffalo could still be seen in the plat of Lincoln in the 1860s. Lincoln was founded in 1856 as the village of Lancaster and became the county seat of the newly created Lancaster County in 1859, the village was sited on the east bank of Salt Creek. The first settlers were attracted to the due to the abundance of salt. Once J. Sterling Morton developed his salt mines in Kansas, Captain W. T. Donovan, a former steamer captain, and his family settled on Salt Creek in 1856. In the fall of 1859, the settlers met to form a county. A caucus was formed and the committee, which included Captain Donovan, after the passage of the 1862 Homestead Act, homesteaders began to inhabit the area. The first plat was dated August 6,1864, by the close of 1868, Lancaster had a population of approximately 500 people

4.
Kobe
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Kobe is the sixth-largest city in Japan and is the capital city of Hyōgo Prefecture. It is located on the side of the main island of Honshū, on the north shore of Osaka Bay. With a population around 1.5 million, the city is part of the Keihanshin metropolitan area along with Osaka, the earliest written records regarding the region come from the Nihon Shoki, which describes the founding of the Ikuta Shrine by Empress Jingū in AD201. For most of its history, the area was never a political entity, even during the Tokugawa period. Kobe did not exist in its current form until its founding in 1889 and its name comes from kanbe, an archaic title for supporters of the citys Ikuta Shrine. Kobe became one of Japans 17 designated cities in 1956, Kobe was one of the cities to open for trade with the West following the 1853 end of the policy of seclusion and has since been known as a cosmopolitan port city. While the 1995 Great Hanshin earthquake diminished much of Kobes prominence as a port city, the city is the point of origin and namesake of Kobe beef, as well as the site of one of Japans most famous hot spring resorts, Arima Onsen. Media related to History of Kobe at Wikimedia Commons Tools found in western Kobe demonstrate the area was populated at least from the Jōmon period. The natural geography of the area, particularly of Wada Cape in Hyōgo-ku, led to the development of a port, some of the earliest written documents mentioning the region include the Nihon Shoki, which describes the founding of the Ikuta Shrine by Empress Jingū in AD201. During the Nara and Heian periods, the port was known by the name Ōwada Anchorage and was one of the ports from which imperial embassies to China were dispatched. The city was briefly the capital of Japan in 1180, when Taira no Kiyomori moved his grandson Emperor Antoku to Fukuhara in present-day Hyōgo-ku, the Emperor returned to Kyoto after about five months. Shortly thereafter in 1184, the Taira fortress in Hyōgo-ku and the nearby Ikuta Shrine became the sites of the Genpei War battle of Ichi-no-Tani between the Taira and Minamoto clans, the Minamoto prevailed, pushing the Taira further. As the port grew during the Kamakura period, it became an important hub for trade with China, in the 13th century, the city came to be known by the name Hyōgo Port. During this time, Hyōgo Port, along with northern Osaka and it was not until the abolition of the han system in 1871 and the establishment of the current prefecture system that the area became politically distinct. Hyōgo Port was opened to trade by the government of the Bakufu at the same time as Osaka on January 1,1868, just before the advent of the Boshin War. The region has since been identified with the West and many residences from the period remain in Kobes Kitano area. Kobe, as it is today, was founded on April 1,1889. The history of the city is tied to that of the Ikuta Shrine, and the name Kobe derives from kamube

5.
New York City Subway
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Opened in 1904, the New York City Subway is one of the worlds oldest public transit systems, one of the worlds most used metro systems, and the metro system with the most stations. It offers service 24 hours per day, every day of the year, the New York City Subway is the largest rapid transit system in the world by number of stations, with 472 stations in operation. Stations are located throughout the boroughs of Manhattan, Brooklyn, Queens, the Port Authority Trans-Hudson and the AirTrain JFK, in Manhattan and Queens respectively, accept the subways MetroCard but are not operated by the MTA and do not allow free transfers. Another mass transit service that is not operated by the MTA, the system is also one of the worlds longest. Overall, the system contains 236 miles of routes, translating into 665 miles of track. In 2015, the subway delivered over 1.76 billion rides, averaging approximately 5.7 million daily rides on weekdays and a combined 5.9 million rides each weekend. Of the systems 25 services,22 of them pass through Manhattan, the exceptions being the G train, the Franklin Avenue Shuttle, and the Rockaway Park Shuttle. Large portions of the subway outside Manhattan are elevated, on embankments, or in open cuts, in total, 40% of track is not underground despite the subway moniker. Many lines and stations have both express and local services and these lines have three or four tracks. Normally, the two are used for local trains, while the inner one or two are used for express trains. Stations served by express trains are typically major transfer points or destinations, alfred Ely Beach built the first demonstration for an underground transit system in New York City in 1869 and opened it in February 1870. The tunnel was never extended for political and financial reasons, although extensions had been planned to take the tunnel southward to The Battery, the Great Blizzard of 1888 helped demonstrate the benefits of an underground transportation system. A plan for the construction of the subway was approved in 1894, the first underground line of the subway opened on October 27,1904, almost 36 years after the opening of the first elevated line in New York City, which became the IRT Ninth Avenue Line. The fare was $0.05 and on the first day the trains carried over 150,000 passengers, the oldest structure still in use opened in 1885 as part of the BMT Lexington Avenue Line in Brooklyn and is now part of the BMT Jamaica Line. The oldest right-of-way, which is part of the BMT West End Line near Coney Island Creek, was in use in 1864 as a railroad called the Brooklyn, Bath. By the time the first subway opened, the lines had been consolidated into two privately owned systems, the Brooklyn Rapid Transit Company and the Interborough Rapid Transit Company, the city built most of the lines and leased them to the companies. This required it to be run at cost, necessitating fares up to double the five-cent fare popular at the time, in 1940, the city bought the two private systems. Some elevated lines ceased service immediately while others closed soon after, integration was slow, but several connections were built between the IND and BMT, these now operate as one division called the B Division

6.
Railway platform height
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On a railway, the platform height refers to the height of a railway platform Above Top of Rail. A related term is train floor height which is the height of the floor of the rail vehicle, worldwide, there are a large number of incompatible standards for platform heights and train floor heights. When raised platforms are in use, the width must also be compatible. Differences in platform height can pose a risk for passenger safety, platform ramps, steps, and platform gap fillers together with hazard warnings such as mind the gap are used to reduce risk and enable access. Platform height affects the gauge, and must conform to the structure gauge physical clearance specifications for the system. Tracks which are shared between freight and passenger service must have platforms which do not obstruct either type of railroad car, to reduce station construction costs, many train systems use a low platform, and require passenger cars with internal stairs up to the train floor. Buses, trams, trolleys and railway cars are divided into several typical categories. Trains The majority of systems in Australia use high level platforms with a platform height a small distance below the train floor level. Exception to this include Queensland who have narrow gauge trains and lower platforms, in New South Wales, by 2000, the platform step had been allowed to grow to a maximum of about 300 mm, which was uncomfortably large. For Sydneys 2000 Olympics, new and altered platforms were designed to match the Tangara trains, which are 3,000 mm wide, leaving a gap of about 80 mm. This has become the standard for all subsequent platforms and trains in NSW, the tramway network in Melbourne have some low level platforms and low floor vehicles, but most trams have steps and are boarded from the road. The Gold Coast and Sydney light rail networks have low floor trams and platforms at all stops, chinese platforms are 380 mm,550 mm,760 mm and 1,250 mm. Areas adjacent to broad gauge countries/regions, such as Xinjiang and Inner-Mongolia, platforms on the MTR are 1,250 mm above the rail for the Tung Chung Line and Airport Express, but the height of those on other urban lines is unknown. It seems like all the MTR lines built before the MTR-KCR merger in 2007 have the same specs, platforms on the East Rail Line are 42 in high. Since all the former KCR lines excluding light rail are built to the same specs, iranian platforms are 380 mm,550 mm and 760 mm. Like in China, areas adjacent to broad gauge countries/regions such as the eastern regions such as around Mashhad and Zahedan, north Korean platforms are standardized at 1,250 mm only. In there,1,250 mm is the norm, lower-level platforms are already raised to this height, typical Korail platforms are 550 mm. Older platforms are lower than 500mm, elsewhere, such as Hokkaido and the Tohoku/Hokuriku region of Honshu,920 mm – and even 760 mm platforms are still commonplace

7.
Bombardier Transportation
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Bombardier Transportation is the rail equipment division of the Canadian firm Bombardier Inc. Bombardier Transportation is one of the worlds largest companies in the rail vehicle, the division is headquartered in Berlin, Germany, and has regional offices and major development facilities in Canada and the United States. Bombardier Transportation has many production and development facilities worldwide. Bombardier Transportation produces a range of products including passenger rail vehicles, locomotives, bogies, propulsion and controls. Laurent Troger is the president and chief operating officer of Bombardier Transportation, in January 2011, the company had 34,900 employees,25,400 of them in Europe, and 60 manufacturing locations around the world. Bombardier Transportations first order for mass transit rolling stock was in 1974 for the Société de transport de Montréal to build trains for the Montreal Metro. The core of the Transportation group was formed with the purchase of Montreal Locomotive Works in 1975, with that purchase, Bombardier acquired MLWs LRC tilting train design which it produced in the 1980s. The group also purchased Urban Transportation Development Corporation from the Government of Ontario, MLW was sold to General Electric in 1988. GE ended railcar operations in Canada in 1993, Bombardier Transportation continues to operate the railcar operations in Thunder Bay. In 1987, Bombardier bought the assets of US railcar manufacturers Budd, in 1990, Procor Engineering Ltd. of Horbury near Wakefield, UK, a manufacturer of bodyshells, was acquired, and renamed Bombardier Prorail. In 1991, the grouping Bombardier Eurorail was formed consisting of the companys European subsidiaries, BN, ANF-Industrie, Prorail, in 1992, the company acquired Mexicos largest railway rolling-stock manufacturer, Concarril, from the Mexican government. In 1995, Waggonfabrik Talbot KG in Aachen, Germany, and in 1998, Deutsche Waggonbau AG, DWA encompassed the major portion of the railway equipment industry of the former East Germany, and had its principal sites in Bautzen and Görlitz. In 2001, Bombardier Transportation acquired Adtranz from DaimlerChrysler, and became by many measurements the Western worlds largest rail-equipment manufacturer, the addition of ADtranz made Bombardier a manufacturer of locomotives along with its existing product lines of passenger carriages, multiple-unit trains, and trams. With the acquisition of ADtranz, Bombardier also gained competence in the propulsion components business. Other sites had their work reduced in scope, or were closed. In Sep 2014 the downsizing and eventual closure of the Maryborough factory was announced, in January 2015, the government of Hungary nationalised the loss-making and under-utilised Bombardier carriage works at Dunakeszi, acquiring a 64. 9% stake for $7.8 million. An IPO was planned for late 2015, the investment initially representing a 30% stake - a valuation of $5 billion. The sale was required in part to continue the financing of the parent companys C-Series jet, in Aug 2016 Bombardier opened a 6,000 square metres production facility in Isando, Johannesburg, South Africa

8.
Electric motor
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An electric motor is an electrical machine that converts electrical energy into mechanical energy. The reverse of this is the conversion of energy into electrical energy and is done by an electric generator. In normal motoring mode, most electric motors operate through the interaction between an electric motors magnetic field and winding currents to generate force within the motor, small motors may be found in electric watches. General-purpose motors with highly standardized dimensions and characteristics provide convenient mechanical power for industrial use, the largest of electric motors are used for ship propulsion, pipeline compression and pumped-storage applications with ratings reaching 100 megawatts. Electric motors may be classified by electric power source type, internal construction, application, type of motion output, perhaps the first electric motors were simple electrostatic devices created by the Scottish monk Andrew Gordon in the 1740s. The theoretical principle behind production of force by the interactions of an electric current. The conversion of energy into mechanical energy by electromagnetic means was demonstrated by the British scientist Michael Faraday in 1821. A free-hanging wire was dipped into a pool of mercury, on which a permanent magnet was placed, when a current was passed through the wire, the wire rotated around the magnet, showing that the current gave rise to a close circular magnetic field around the wire. This motor is often demonstrated in experiments, brine substituting for toxic mercury. Though Barlows wheel was a refinement to this Faraday demonstration. In 1827, Hungarian physicist Ányos Jedlik started experimenting with electromagnetic coils, after Jedlik solved the technical problems of the continuous rotation with the invention of the commutator, he called his early devices electromagnetic self-rotors. Although they were used only for instructional purposes, in 1828 Jedlik demonstrated the first device to contain the three components of practical DC motors, the stator, rotor and commutator. The device employed no permanent magnets, as the fields of both the stationary and revolving components were produced solely by the currents flowing through their windings. His motor set a record which was improved only four years later in September 1838 by Jacobi himself. His second motor was powerful enough to drive a boat with 14 people across a wide river and it was not until 1839/40 that other developers worldwide managed to build motors of similar and later also of higher performance. The first commutator DC electric motor capable of turning machinery was invented by the British scientist William Sturgeon in 1832, following Sturgeons work, a commutator-type direct-current electric motor made with the intention of commercial use was built by the American inventor Thomas Davenport, which he patented in 1837. The motors ran at up to 600 revolutions per minute, and powered machine tools, due to the high cost of primary battery power, the motors were commercially unsuccessful and Davenport went bankrupt. Several inventors followed Sturgeon in the development of DC motors but all encountered the same battery power cost issues, no electricity distribution had been developed at the time

9.
Railway electrification system
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A railway electrification system supplies electric power to railway trains and trams without an on-board prime mover or local fuel supply. Electrification has many advantages but requires significant capital expenditure, selection of an electrification system is based on economics of energy supply, maintenance, and capital cost compared to the revenue obtained for freight and passenger traffic. Different systems are used for urban and intercity areas, some electric locomotives can switch to different supply voltages to allow flexibility in operation, Electric railways use electric locomotives to haul passengers or freight in separate cars or electric multiple units, passenger cars with their own motors. Electricity is typically generated in large and relatively efficient generating stations, transmitted to the railway network, some electric railways have their own dedicated generating stations and transmission lines but most purchase power from an electric utility. The railway usually provides its own lines, switches and transformers. Power is supplied to moving trains with a continuous conductor running along the track usually takes one of two forms. The first is a line or catenary wire suspended from poles or towers along the track or from structure or tunnel ceilings. Locomotives or multiple units pick up power from the wire with pantographs on their roofs that press a conductive strip against it with a spring or air pressure. Examples are described later in this article, the second is a third rail mounted at track level and contacted by a sliding pickup shoe. Both overhead wire and third-rail systems usually use the rails as the return conductor. In comparison to the alternative, the diesel engine, electric railways offer substantially better energy efficiency, lower emissions. Electric locomotives are usually quieter, more powerful, and more responsive and they have no local emissions, an important advantage in tunnels and urban areas. Different regions may use different supply voltages and frequencies, complicating through service, the limited clearances available under catenaries may preclude efficient double-stack container service. Possible lethal electric current due to risk of contact with high-voltage contact wires, overhead wires are safer than third rails, but they are often considered unsightly. These are independent of the system used, so that. The permissible range of voltages allowed for the voltages is as stated in standards BS EN50163. These take into account the number of trains drawing current and their distance from the substation, railways must operate at variable speeds. Until the mid 1980s this was only practical with the brush-type DC motor, since such conversion was not well developed in the late 19th century and early 20th century, most early electrified railways used DC and many still do, particularly rapid transit and trams

10.
Volt
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The volt is the derived unit for electric potential, electric potential difference, and electromotive force. One volt is defined as the difference in potential between two points of a conducting wire when an electric current of one ampere dissipates one watt of power between those points. It is also equal to the difference between two parallel, infinite planes spaced 1 meter apart that create an electric field of 1 newton per coulomb. Additionally, it is the difference between two points that will impart one joule of energy per coulomb of charge that passes through it. It can also be expressed as amperes times ohms, watts per ampere, or joules per coulomb, for the Josephson constant, KJ = 2e/h, the conventional value KJ-90 is used, K J-90 =0.4835979 GHz μ V. This standard is typically realized using an array of several thousand or tens of thousands of junctions. Empirically, several experiments have shown that the method is independent of device design, material, measurement setup, etc. in the water-flow analogy sometimes used to explain electric circuits by comparing them with water-filled pipes, voltage is likened to difference in water pressure. Current is proportional to the diameter of the pipe or the amount of water flowing at that pressure. A resistor would be a reduced diameter somewhere in the piping, the relationship between voltage and current is defined by Ohms Law. Ohms Law is analogous to the Hagen–Poiseuille equation, as both are linear models relating flux and potential in their respective systems, the voltage produced by each electrochemical cell in a battery is determined by the chemistry of that cell. Cells can be combined in series for multiples of that voltage, mechanical generators can usually be constructed to any voltage in a range of feasibility. High-voltage electric power lines,110 kV and up Lightning, Varies greatly. Volta had determined that the most effective pair of metals to produce electricity was zinc. In 1861, Latimer Clark and Sir Charles Bright coined the name volt for the unit of resistance, by 1873, the British Association for the Advancement of Science had defined the volt, ohm, and farad. In 1881, the International Electrical Congress, now the International Electrotechnical Commission and they made the volt equal to 108 cgs units of voltage, the cgs system at the time being the customary system of units in science. At that time, the volt was defined as the difference across a conductor when a current of one ampere dissipates one watt of power. The international volt was defined in 1893 as 1/1.434 of the emf of a Clark cell and this definition was abandoned in 1908 in favor of a definition based on the international ohm and international ampere until the entire set of reproducible units was abandoned in 1948. Prior to the development of the Josephson junction voltage standard, the volt was maintained in laboratories using specially constructed batteries called standard cells

11.
Third rail
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A third rail is a method of providing electric power to a railway locomotive or train, through a semi-continuous rigid conductor placed alongside or between the rails of a railway track. It is used typically in a transit or rapid transit system. Third rail systems are supplied from direct current electricity. The third-rail system of electrification is unrelated to the third used in dual gauge railways. Third-rail systems are a means of providing electric power to trains. On most systems, the rail is placed on the sleeper ends outside the running rails. The conductor rail is supported on ceramic insulators or insulated brackets, the trains have metal contact blocks called shoes which make contact with the conductor rail. The traction current is returned to the station through the running rails. The conductor rail is made of high conductivity steel. The conductor rails have to be interrupted at level crossings, crossovers, tapered rails are provided at the ends of each section, to allow a smooth engagement of the trains contact shoes. Because third rail systems present electric shock hazards close to the ground, a very high current must therefore be used to transfer adequate power, resulting in high resistive losses, and requiring relatively closely spaced feed points. The electrified rail threatens electrocution of anyone wandering or falling onto the tracks. This can be avoided by using platform screen doors, or the risk can be reduced by placing the rail on the side of the track away from the platform. There is also a risk of pedestrians walking onto the tracks at level crossings, the Paris Metro has graphic warning signs pointing out the danger of electrocution from urinating on third rails, precautions which Chicago did not have. The end ramps of conductor rails present a practical limitation on speed due to the impact of the shoe. The world speed record for a rail train is 174 km/h attained on 11 April 1988 by a British Class 442 EMU. In the event of a collision with an object, the beveled end ramps of bottom running systems can facilitate the hazard of having third rail penetrate the interior of a passenger car. This is believed to have contributed to the death of five passengers in the Valhalla train crash of 2015, third rail systems using top contact are prone to accumulations of snow, or ice formed from refrozen snow, and this can interrupt operations

Triple gauntlet track at Kaufungen, Germany. Wider mainline trains go down the centre; narrower trams switch either to the left, or right, to be closer to the relevant platform. Beyond the station, the rails return to single track.

A third rail is a method of providing electric power to a railway locomotive or train, through a semi-continuous rigid …

Third rail at the West Falls ChurchMetro station near Washington, D.C., electrified at 750 volts. The third rail is at the top of the image, with a white canopy above it. The two lower rails are the ordinary running rails; current from the third rail returns to the power station through these.